#include<bits/stdc++.h>
#define ll long long
#define ull unsigned long long
using namespace std;

const ll N = 1e6 + 10, INF = 0x3f3f3f3f;

ll cnt1(ll x)
{
    ll cnt = 0;
    while (x) {
        if (x & 1) cnt++;
        x >>= 1;
    }
    return cnt;
}

ll cnt0(ll x)
{
    ll cnt = 0;
    while (x) {
        if ((x & 1) == 0) cnt++;
        x >>= 1;
    }
    return cnt + 1;
}

void solve()
{
    ll x; cin >> x;
    for (ll j = 1;j <= 1000000;j++) x = cnt0(cnt1(x));
    if (x == cnt0(cnt1(x))) cout << x;
    else cout << -1;
}

signed main()
{
    // ios::sync_with_stdio(0);
    // cin.tie(0);cout.tie(0);
    // #define ONLINE_JUDGE
#ifndef ONLINE_JUDGE
    std::istringstream in(R"()");
    std::cin.rdbuf(in.rdbuf());
#endif
    ll T = 1;
    //cin>>T;
    for (ll i = 1;i <= T;i++) {
        solve();
    }
}